1. Field of the Invention
This invention pertains to sporting gun cartridges, such as cartridges that are useful with shotguns for example. In particular, the invention pertains to cartridges that have a special wad, commonly known for example as shotshell wad, of believed superior design.
2. Brief Description of Prior Art
Tangentially related to the present invention are two known U.S. Pat. Nos. as follows: 1,864,916, issued Jun. 28, 1932 and 3,516,360, issued Jun. 23, 1970. U.S. Pat. No. 3,974,775, issued Aug. 17, 1976, teaches the concept of separable forward fins, but this defeats the close shot pattern made possible by the closed, unsegmented, essentially cylindrical wad forward extremity in the present invention.
Cartridges for sporting guns such as shotguns is a well developed art. Earlier cartridges did not employ shotshell wads since lead shot was used. Lead, being a soft metal, would not score the interior of the barrel of the shotgun. However, the art progressed where steel pellets were employed in lieu of lead shot, and steel, being a harder material than lead, would score and damage the interior of the bore. Because of this, shotshell wads made of plastic were developed for the purpose of carrying the shot forwardly along the interior of the barrel without the shot coming in direct contact with the bore surface. Upon firing, then, the wad would proceed forwardly containing the shot and, once the muzzle area was reached, the plastic wad would advance forwardly with the shot but, hopefully, would gradually drop down out of the line of fire. A problem has occurred in connection with the wad tumbling, which would have an effect of distorting the flight pattern of the shot from that intended. More seriously, upon firearm firing, shot or pellets in the forward portion of the wad will tend to hang up or experience impaction within the wad in the presence of air pressure pressing rearwardly against the shot, and the increased shot-wad frictional effects resulting therefrom and from shot inertia under initial conditions retard shot separation from the wad at and beyond the muzzle location. The present invention overcomes this difficulty by scoring the forward portion of the shotshell wad wall, rearwardly of the latter's forward end, in a manner to delineate the series of wall segments proximate the area containing the shot or pellets. This will be described more fully hereinafter. At this point, and what the prior art does not teach, is the concept of providing a wad having delineated forward wall segments, stopping short of the wad forward closed end--thereby maintaining the integrity of such end--to produce a restricted shot pattern; in one form of the present invention, the rear tubular portion of the wad can include rearwardly oriented fins, see the applicant's co-pending U.S. patent application Ser. No. 09/313,312, filed May 5, 1999, fully incorporated herein by way of reference herein, so that once the muzzle area is reached, such fins will fan outwardly and peripherally about the wad so as to direct its flight and likewise, secondarily, supply an aerodynamic frictional drag whereby to permit the wad to drop behind and then fall out of the advancing shot. This latter feature, relating to the rearwardly directed fins, may not be strictly necessary, depending upon wad dimensions, the nature of the charge of shot, pellets, etc.